I recently learned of this game at a house party, and then later played it on a car trip for a couple of hours. The basic mechanics are guessing and trivia, with some know-your-opponents aspects as well. It's a decent game for building vocabulary, and stresses verbal creativity. It requires 3 or more players, and I think it plays best with 4-5 (road trip, anyone?). The internet has exposed me to a number of variations already, so I'll start with a description of the most basic game and then describe as many variants or additional rules as I can.

You, whose turn it is, choose a word. You give us, the other players, the first letter of the word. We then take turns making up a (probably different) word that starts with your letter and giving you a clue as to our word. You have to guess our word based on our clue or else give us the next letter of your word. However, a clue is only valid if someone ELSE in the group can also figure it out. When I give a clue, while you think about it I need someone else to say "Contact" to indicate that they understand my clue and have guessed my word. After this, there is some (varied based on version of the game) time for you to figure out my clue. When you give up or run out of time, myself and the person(s) who said Contact all answer my clue at the same time. If we actually say the same word (which might not happen if they mistook my clue), then you've failed and must give us the next letter of your word. The ONLY requirement for a valid clue is that someone can understand it. It can be as vague or oddly worded as you like, and coming up with clues to relatively common words that are not immediately obvious is an important part of the game. This process repeats until we can actually guess your word by forcing you to give us enough letters, at which point another word is chosen and the game begins anew.

Variations:Acceptable words might be unlimited, or specific to a language or specialty vocabulary, or exclude proper nouns, or limited only to nouns. Prefixes should be forbidden.The current player, who choses THE word, can be chosen at random, can proceed around the table, or can pass to whoever guessed the previous player's word.The person making up a word and clue can proceed around the table or can simply be whoever thinks of a good clue next (It's not as easy as it sounds! Often only one player will have a clue, and there may even be pauses).The time given to the current player to answer a clue can be just a few seconds after someone else says Contact, or it can be as long as they need, or other criteria can come into play.Whether the current player has to guess the current clue'd word exactly, or just give any of multiple accurate answers (a yellow flower that starts with DA might be daisy or daffodil or dandelion). If they get one correct answer, can the same clue be given again? By the same player?

If you play this game with just three players, and they do not share a specialist vocabulary, then there will be many clues that stump both the current player and the only other player. If you play with many players then many clues will result in Contact while stumping the current player, leading to shorter rounds. More players also means more people will think of clues at the same time and be frustrated at not getting to present them.

I'd love to hear about more variations of this game from people who've played it before, particularly ways to make it work better with larger groups of people (10+). I'd also like to hear about games that are similar to this, like Botticelli (same game, but for famous people). Games you can play with just a group of people, no dice or cards or boards, are a useful thing to know about, and sometimes the mechanics of "I Spy" and "20 Questions" just aren't enough to keep me interested for more than a few minutes. I hope someone else out there gets some mileage out of "Contact" and learns some new words along the way.